This proposal seeks support for the thirty-fourth in an annual series of meetings on "Retroviruses" to be held at Cold Spring Harbor Laboratory that has emerged as the premiere conference for this field. The proposed meeting will assemble leaders in the field, junior faculty, postdoctoral fellows and graduate students to discuss new, cutting-edge developments in the field of retroviral biology. The meeting series is focused on the viruses rather than their host or the particular disease they cause. The large majority of the work to be presented will be unpublished and subject to immediate comment and discussion by the audience. The 2009 meeting will be structured in a manner that parallels the biology of the viruses;beginning with the entry phase of the replication cycle, proceeding with post-entry events, assembly and release, integration, reverse transcription, pathogenesis/host factors, RNA-related events (transcription, processing, export, and packaging) and finishing with antivirals. Each session will be chaired by two leading scientists in the field selected from amongst the registered attendees. Oral presentations will be selected by the organizers and session chairs in consultation with the organizers. Selected speakers will include graduate students, postdoctoral fellows and junior faculty. Two special lectures will be presented to provide essential background critical to stimulating discussion between scientists working on related but distinct areas. There will also be three poster sessions where a majority of participants can present their work. The meeting will be of moderate size, and we expect 400-450 retrovirologists in attendance.